Hair cosmetics such as a rinse, conditioner, treatment, etc. are used for improving the feel of hair after shampooing. These hair cosmetics contain a quaternary ammonium salt as a main component to improve the feel of hair, and are used mainly in the form of a gelled emulsion by further incorporation of an aliphatic alcohol such as cetanol or an oil to improve efficacy feeling. However, these hair cosmetics cannot be said to provide a sufficient smooth feel and moist feel to hair.
It was found in recent years that a specific amideamine compound or its acid salt can confer smooth feel and softness on hair, and hair cosmetics containing the amideamine compound or its acid salt have been proposed (see, for example, JP-A 5-271035, JP-A 5-271036 and WO-A 2004/030646).
The amideamine compound or its salt is also known to provide hair cosmetics which are highly safe and show a mild action on skin etc. (see FRAGRANCE JOURNAL, 24(12), 106-111 (1996)). Further, stearic acid dimethylaminopropylamide is known as a specific amideamine.
In recent years, it has become common to enjoy changing the appearance of hair freely such as changing hair color (coloring) and changing hair style (permanent waving), and damage to hair such as a dry and frictional feel and entanglement, attributable to such practice, has been drawing attention. It is estimated that damage to hair by coloring treatment or permanent waving treatment is caused by chemical factors forming cavities in the hair with a hair dye or permanent waving agent used for the treatment. It is also said that damage to hair, such as the absence of luster, a dry and frictional feel, etc. is caused by the formation of cavities in the hair by physical factors such as heating with a dryer for drying hair after shampooing.
For repairing the damaged hair, hair cosmetics containing water-insoluble cationic fine particles (JP-A 10-72324) and hair cosmetics containing an amino acid-based amphoteric surfactant and a naturally occurring triglyceride to repair hair (JP-A 2000-86454) have been proposed. For preventing damage, hair cosmetics containing phytantriol and silicone (U.S. Pat. No. 5,776,443), hair cosmetics containing dimethyl silicone gum, polyethylene glycol and a cationic surfactant (JP-A 4-279512), and hair cosmetics containing hydrolyzed wheat proteins, wheat oligosaccharides, wheat amino acids and panthenol (JP-A 8-157332) have been proposed.
For improving optical properties such as hair luster, various hair cosmetics containing components such as an organopolysiloxane oxyalkylene copolymer and acrylic resin have been proposed (JP-A 55-33745).
Hair cosmetics using a cationic surfactant etc. in combination with a polyhydric alcohol, hydroxypropyl cellulose etc. to confer luster on hair are also proposed (JP-B 2998027).
Any conventional methods of repairing hair are those making hair repair felt temporarily by repairing the cuticle edge on the surface of hair or by adsorbing an oil onto the surface of hair, but not those capable of repairing or preventing cavities in the hair, which are an essential cause for damage.
Also, JP-A 55-33745 supra is to improve optical properties by allowing the hair cosmetics to act on the surface of hair or on cuticles in the vicinity thereof, and its effect is temporary and insufficient. JP-B 2998027 also has problems in feeling upon use by application to hair, for example in smoothness, etc.
Further, compositions when blended with other components such as an aliphatic alcohol or an oil are problematic in stability, for example in gel formability, and cannot be satisfactory in smoothness and moist feel to be conferred on hair.